I've had a problem with mine not much air blowing out the vents for some time and the DW commented on it this weekend (95f) so I went searching like you ,under the dash and found that both hvac motors and linkage were working properly. For anyone who is troubleshooting this the blend motors are on each side of the center console ,very easy to see and also to reach up and manually check, 1 on each side .Then I decided to look in the glove box filter to see what I could find and wow did I find the problem,it was the filters they must of been never changed , after a few minutes of blowing and vacuming them out the problem was fixed. I am going to to get a large filter and cut it down to fit into the opening (to cheap to buy the proper replacements)Will report back with my findings.